The invention relates to a method for manufacturing highly heat-resistant polyimidazole and polyimidazopyrrolone relief structures by applying radiation-sensitive soluble polymer precursors to a substrate in the form of a layer or foil, irradiating the layer or foil through negative patterns with actinic light or electrons, or by guiding a light, electron, ion, or laser beam, removing the non-irradiated layer or foil portions, and optionally subsequently annealing the remaining portions; as well as to the use of these relief structures.
From U.S. Pat. No. 4,332,882, a method of the type mentioned above for manufacturing highly heat-resistant polyimidazole and polyimidazopyrrolone relief structures is known. In this method, addition products of olefinically unsaturated monoepoxides and eitner: (a) amino group--containing polycondensation products prepared from reacting aromatic and/or heterocyclic tetramino compounds with dicarboxylic acid chlorides or esters, or (b) amino group-containing poly-addition products of the tetraamino compounds and tetracarboxylic acid dianhydrides are used as polymer precursors.
The relief structures prepared by the known method are characterized by special properties. Thus, they withstand heating processes up to 450.degree. C. and are also resistant to heavy radiation in extended operation. The known relief structures are also suitable as masks for the fine structuring of substrates by wet chemistry, for instance, by alkaline or acid etching. In the known method the processing properties of the polymer precursors are not yet quite satisfactory; in particular, their photosensitivy is limited.